The importance of the difference between the two raceways of the double row ball slewing bearing

Slewing bearings have unique load characteristics and are usually used in hoisting machinery, excavators, slewing tables, wind turbines and other equipment. The four point contact ball structure slewing bearing below three meters is mostly, load size determines the slewing bearing’s height, diameter and the size of the raceway steel ball.

If a large load slewing ring is required but the diameter size is limited, the load capacity of the slewing ring can generally be increased by increasing the steel ball, if the increased steel ball still fails to meet the load requirements, you can use double row ball slewing ring. The double row ball slewing ring meets the limitation of outer diameter, which also requires large load use requirements. Not only saves materials, but also improves the slewing bearing performance, so that the slewing ring has greater axial load, radial load and tilting moment.

So how to ensure the double row ball slewing bearing’s accuracy and grading tolerance? Next, Unique Transmission will give you an introduction.

The raceway of the slewing bearing is divided into plane raceway and arc raceway. The raceways of four point contact ball slewing bearings and double row ball slewing bearings are typical arc raceways; The raceway of crossed roller slewing bearings and three row roller slewing bearings are typical flat raceways. In terms of processing technology, the processing difficulty of arc raceway is greater than flat raceway, so the accuracy level and actual processing parameter control naturally have higher requirements.

Especially for double row ball slewing rings, the raceway is two parallel arcs. Theoretically, the two rows of balls receive force and run at the same time during the rotation process. However, the probability of absolute simultaneous force and simultaneous operation is very low, it’s only exists in theory. In the process of processing, a certain error is allowed for the double row ball raceway.

This error is not enough to affect the overall operating state of the slewing ring, and it can basically ensure that the double volleyball is under force at the same time, and the rotation is flexible and smooth. This error is not enough to affect the overall operating state of the slewing bearing. It can basically ensure that the double row balls are stressed at the same time and rotate flexibly and smoothly.

This grading tolerance is generally required to be within 0.03mm in process. In order to achieve this goal, in the process of slewing ring grinding and matching, the machine tool needs to have good accuracy and the workers need to have a skilled operation level. If you want to achieve double row ball slewing ring has zero clearance or negative clearance, the grading tolerance needs to be controlled within 0.01mm. For double row ball slewing rings, only by controlling the grading tolerance of the raceways can the slewing ring display its theoretical load capacity and its characteristics.